1. Field of the Invention
The present invention relates to a fabric fastener having a plurality of male projections on its surface and utilized for fastening a mating object having a rough surface by the engagement of the male element with the latter surface.
2. Description of Related Arts
A fabric fastener of the described type is widely known. Typical examples thereof are disclosed, for example, in Japanese Examined Patent Publication Nos. 35-552 and 46-5417, in which the fastener comprises a male member with a plurality of hook or mushroom shape projections as shown in FIG. 1 projecting from a surface thereof and a female member with a plurality of loops on a surface thereof, whereby both members are releaseably engaged with each other when the male and female members are piled and pressed together, thus achieving the fastening effect between the both members.
The above type of the fabric fastener is mainly used for fastening clothing, diapers, shoes or the like due to its softness. Recently, however, an increasing requirement for the industrial use thereof has arisen, such as for fixing an interior of automobile, or for detachably fastening a working element to a rotor of a polisher or a grinder. Especially, in the case of the polisher, the working element is a mat in which fibers are randomly oriented and fixed to each other with adhesive to form a relatively porous structure, or a sponge formed of a synthetic resin foam. For fastening such an element, it is sufficient to use the male member only, without the female member, because the mat or sponge type working element itself acts as a female member. In such a case, the male member of the fabric fastener is required to have a specific property different form that of the conventional fastener comprising two members selected to be most suitably engageable to each other. That is, the single member must be engageable with any type of working elements, each made of a different material and having a different porosity, hardness, and elasticity from the other.
Under such circumstances, according to experiments conducted by the present inventors, it was found that the conventional male member is unsatisfactory for fastening a working element formed of a mat or a sponge, because, on one hand, it is difficult for the hook shape projection to enter a gap between th mat forming fibers or a recess of the sponge and, conversely, although the mushroom shape projection is relatively easily engageable with the gap or void of the working element, it is difficult to detach the same therefrom and, if this is forcibly carried out, the engaging surfaces are liable to be damaged and are quickly worn out.